Presidents can't declare war? Just watch them

War is the purview of Congress, but try telling that to the commander in chief.

It really couldn't be clearer. "The Congress shall have power … to declare war." Yet these are probably the most egregiously ignored words in the Constitution. You would think that Republicans, especially, with their showy fondness for "originalism" and "plain meaning" in interpreting the Constitution, would have no problem interpreting the meaning of these words: If a president wants to go to war, he must get the approval of Congress.

Presidents of both parties traditionally ignore the congressional war power when they feel like it. Or they wait until the troops are poised for battle — putting Congress in an impossible position — before asking permission.

One good thing that may come out of our Libyan adventure is a renewed appreciation by Republicans of the Constitution's limits on a president's power to take the country into battle. Of course, this must be balanced against the Democrats' renewed amnesia about the same thing.

Then there is the War Powers Act, enacted by a Democratic Congress over President Nixon's veto, basically giving the president 90 days after the start of hostilities to come to Congress for approval. At the time, this was widely believed to be unconstitutional because it gave too much independent power to the president. More recently, presidents have felt free to ignore the War Powers Act because, they say, it unconstitutionally restrains the commander in chief.

It's the Constitution that anoints the president as commander in chief. But the notion that this gives him unilateral authority to take this country into war — while, by contrast, the congressional power to declare war places no limits on the president's authority to do the same — puts you in Humpty Dumpty territory, where a word "means just what I choose it to mean, neither more nor less." A commander at any level doesn't get to choose the enemy.

It used to be argued, before presidents stopped even bothering to argue the point, that the congressional war power was outmoded in a century when the war was likely to start with a surprise attack. The Russians could obliterate 20 American cities in the time it took for Sen. Slowbrain to conclude his opening remarks at the first of half a dozen hearings.

But constitutional provisions don't disappear just because they seem outmoded, and in this case, the provision is not even outmoded. As it has turned out, the characteristic American war of the 21st century is perfectly suited to the constitutional requirements. Typically, something horrible is going on far away, and we have to decide whether to intervene. There is no element of surprise on either side. The decision to go to war is ours. That decision is usually made slowly, deliberately and more or less publicly, with officials popping up all over TV explaining and justifying. Libya was a bit hastier than average, but there still could have been time for a congressional resolution, if the president thought it was required, which he clearly doesn't.

But he used to. As John Dickerson points out in Slate, President Obama has flip-flopped on this issue just as egregiously as Newt Gingrich (although not as quickly). He said in 2007, "The president does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation." As Bruce Ackerman points out in Foreign Policy, Obama's flouting of the war power is arguably more egregious than George W. Bush's because Bush did in the end get authorization (claiming all along that he didn't need to).

You might ask why, if this is all so clear, the Supreme Court has never said so. How have so many presidents gotten away with it? Goodness, with all the lawyers around, can't someone sue? The answer is that yes, of course you can sue. Anybody can sue anyone about anything. But that doesn't mean you can win. No court — certainly not the Supreme Court — will try to stop a presidential war in progress. They'll say it's a political question. Or it's a dispute between the other two branches and the court won't interfere. Or the plaintiff lacks standing to sue.

We're so used to judicial review — judges overturning laws and other actions by the government — that we tend to think that judges always get the last word on what the law is. And we find it hard to wrap our heads around the idea that something can be the law, even when it can't be enforced. Intervening in an argument between the president and Congress and trying to stop a war in progress is something the Supreme Court is unlikely to do. And that's OK — provided that the other two branches fulfill their own independent duty to uphold the Constitution.

It's a mystery why presidents even want the unilateral power to take this country into war. That must surely be the most terrible decision a president has to make. You would think that having to share the credit is a small price to pay for getting to share the risk. And why should members of Congress get to mouth off about war all day, but not have to take shared responsibility for the yes-or-no decision?

Michael Kinsley, a former editorial page editor of The Times, writes a column for Politico. A version of this column also appears on that website.